The invention relates to a pump with a pipe through which fluid is conveyed, the pipe on the inlet side having a first segment with a delivery cross section which cannot be changed, and with a means for producing transverse oscillations in the fluid.
In pumps the fluid to be delivered is conventionally conveyed via translationally moved parts, for example, pistons, or rotationally moving pump wheels. Pumping fluids by displacement of the fluid in a deformable tube, for example by squeezing the tube together, is also known.
These known pumps except for the latter type of pump have the disadvantage that in the area of the fluid to be conveyed wear phenomena and possibly contamination of the fluid arise due to the components sliding against one another, or seal problems must be solved. Nor is it easily possible to convey for example sludges with coarse portions, for example, stones, by rotating parts or valves.
U.S. Pat. No. 2,888,877 and DE 956 020 C disclose pumps which on the inlet side have a rigid pipe. Furthermore there are pump devices. In U.S. Pat. No. 2,888,877 this is a sine wave-shaped element and in DE 956 020 C a piston or an elastic pipe piece which can be squeezed together. In U.S. Pat. No. 2,888,877 the pump action takes place by the cross section of the pipe always being closed at one point by the sine wave-shaped element and repeated, progressive motion of this point producing the pump action. In DE 956 020 C the pump action takes place by different friction resistances and inertial forces in the two pipe sections with different diameters.
WO 00/62838 A2 describes a pump in which on either side of a middle segment in which the pump action is produced by the external action of a force there are elastically deformable pipe or tube sections. The varied elasticity behavior of these two segments results in different pressures in these segments so that in the elastic contraction of the two segments pump action in one direction or the other takes place. On either side, any, i.e. both rigid and also elastic pipes, can be connected to the two elastic segments.
Therefore the object of the invention is to make available a pump which avoids the described disadvantages as much as possible.